Display shows E3 and the compressor or fan may not run correctly; unit may shut down prematurely.

Safety warning: Disconnect power before accessing the evaporator or control board. Surfaces may be sharp and may have residual ice.

Steps to address E3:

• Defrost the unit: Unplug the cooler and leave the door open for several hours to melt any ice buildup around the evaporator and defrost sensor.
• Access the evaporator: Remove interior shelves and the rear interior panel to expose the evaporator coil and defrost components.
• Locate the defrost sensor: Look for a small thermistor clipped to the evaporator tubing or attached near the defrost heater. It will have two thin wires leading to the cabinet wall.
• Inspect for damage: Check if the sensor body is cracked, corroded, or has exposed wires. Look for signs of overheating near the defrost heater.
• Check wiring and connector: Trace the sensor wires to the rear of the unit and verify the connector at the main control PCB is secure and clean.
• Test the sensor: With a multimeter, measure resistance at room temperature and compare to typical NTC values. If the reading is open, shorted, or far from spec, the sensor is defective.
• Replace the defrost sensor: Install a Haier-compatible defrost thermistor. Clip it firmly to the same location on the evaporator tubing and ensure good contact. Avoid placing it directly against the heater element.
• Reassemble and test: Reinstall the interior panel, restore power, and monitor for normal operation and absence of the E3 code.

When to seek service: If the sensor and wiring are good but E3 persists, the main control PCB defrost circuit may be faulty and should be checked by a professional.